Laboratory evaluation for vitamin B12 deficiency: the case for cascade testing.
Clin Med Res
; 11(1): 7-15, 2013 Feb.
Article
en En
| MEDLINE
| ID: mdl-23262189
ABSTRACT
OBJECTIVE:
Potential vitamin B(12) deficiency is a common clinical diagnostic problem, and many providers have a low threshold for initiating therapy. The goal of this study was to systematically evaluate current practice patterns regarding the laboratory evaluation of suspected vitamin B(12) deficiency.METHODS:
This retrospective study reviewed the electronic medical records of 192 patients initiated on intramuscular vitamin B(12) injections.RESULTS:
Only 12 patients had objectively documented hematologic responses decrease of mean corpuscular volume by ≥5 fL with stable or improved hemoglobin. Another 5 patients had equivocal hematologic responses. There was one plausible neurologic response. Thus, only 18 (9.4%) of 192 patients had data supportive of a clinical response. In these 18 patients, the baseline serum B(12) level was ≤107 pg/mL; only 3 patients also had a baseline serum methylmalonic acid level, which was ≥1.29 µmol/L in all 3 patients.CONCLUSIONS:
Currently, only a small minority of patients initiated on intramuscular vitamin B(12) supplementation derive any meaningful clinical benefit. Furthermore, current testing recommendations for vitamin B(12) deficiency are usually not followed. Up-front ordering of a diagnostic testing cascade is recommended to improve compliance; an example is presented with decision points chosen to improve specificity for clinically evident vitamin B(12) deficiency without loss of sensitivity. Ultimately, a better understanding of vitamin B(12) physiology is needed to develop and evaluate laboratory tests that more accurately reflect true intracellular vitamin B(12) status.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Vitamina B 12
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Deficiencia de Vitamina B 12
Tipo de estudio:
Guideline
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Observational_studies
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Prognostic_studies
Límite:
Adolescent
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Adult
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Aged
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Aged80
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Clin Med Res
Año:
2013
Tipo del documento:
Article
País de afiliación:
Estados Unidos